The data in this edition of the Mobile Internet
Phenomena Report is drawn from Sandvine’s installed
base of mobile operators worldwide. The report does
not include significant data from either China or India,
but the data represents a portion of Sandvine’s 2.5B
subscribers installed base, a statistically significant
segment of the internet population.

https://www.sandvine.com/press-releases/sandvine-releases-2020-mobile-internet-phenomena-report-youtube-is-over-25-of-all-mobile-traffic?fbclid=IwAR2az0RqyVg8b1vRPtG6y-jKlvQKrbq_zESmKb_IJp5ZeU48qApzklQekbI